Improvement in steam-engine-governor cut-offs



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GEORGE MILBANK, OF OH-ILIJIOOT'HE, MISSOURI.

Letters Patent 4No. 99,220, dated .Tantra/ry 25, 1870; antedated January 14, 187 0.

IMPROVEMENT IN STEAM-ENGINE-G-OVERNOR CUT-OFFS.

o y The Schedule referred to n these Letters Patent and making part of the same.

'To all` whom 'it may concern:-

Be it`known that I, GEORGE MILBANK, of Chillicothe, Livingston county, in the State of Missouri, have made certain new and useful Improvements-in Governor Out-Od' for lSteam-lilngines; and I do hereby declare the following' to be a full and true description thereof, reference being had to the accompanying drawings, and to the letters of reference marked'there- This invention relates to the method of cutting oil' the steam from the cylinder by a cut-oil` valve, said valve being controlled by a suitable governor and slotted cam-plate, so that when the speed of the engine is unduly great, the'cut-off valve will be moved by the governor to cut olf steam earlier, thus giving less steam to the cylinder, and causing a corresponding decrease of power, and reduction of speed.

Said invention relates, also, to the arrangementof the cut-olf valve to relieve the same to great extent of steam-pressure, thus permitting a free motion un'- der the impulseof the governor.

To enable 'thosehereinskilled to make and use my said improvements, I 'will now more `fully describe the same, referring herein to the accompanying Figure l as a side elevation, to

Figure-`2 as a plan, to

Figure 3 as a sectional view of the valve-chest and steam-ports.

In igs. 1 and 2, the steam-chest cover is supposed removed, as also the steam-pipe leading to the steamchest.

In the usual application of my said invention, I employ ordinary slide-valves, generally as in the figures shown.

A represents the top of the cylinder', with the valveseats.

a are the steam-ports leading to the frontaud rear of the steam-cylinder, inthe usual manner.

B is .the usual` slide-valve, moving on the seat A, and arranged with the openings l).

Said valve is operated by the -rod B', directly or irrdirectly connected with the main shaft C, by eccentric collar c.

Ordinarily, I prefer to use the rod D, from said eccentric, operating the lever d, and the rock-shaft E. From said lever d, the connecting-rod D', then transmits motion to the valve-stem B', as required.

In order to regulate the amount of steam passing to the cylinder, as in the nature of this invention, I employ the cut-off valve F, moving steam-tightly upon the upper face of the valve B. Said valve F is usually of such length that it will nearly cover both openings 11.A

The valve F is operated by the governor G, in the manner now to be described.

From the sliding collarr` g, which is raised orlowered in accordance with the' speed of the engine, owing to the rotating balls g', in the .manner usual in the centrifugal governor I, operates the lever H, which is pivoted in the standard h. At'its rear end, said lever connects with the link K, upholding the end f of the rod F',` which connects, by a suitable jointed stem, to the valve F.

, The pin f, of therod F', moves in a slot, l, of the vibrating cam-plate L, this being connected tothe rockshaft F, above referred to.

A connecting-rod, M, is actuated by an ecseutric ou the main shaft O, and connects with the cam-plate'L, at one of the several holes l, thps causing said plate to vibrate. The revolution of the shaft C, therebre, causesthe plate L to move the cut-od valve F,"simi larly as the valve B is operated. As, however,y the pin f of the rod F is moved in the slot Z, by the action of the governor, it is plain, that when the pin f stands high in the slot l, the valve F will follow the,l movement of the valve B, thus acting generally as Aa duplicate, but as the pin f drops lower in said slot, the 'movement of the said valves becomes more dissimilar, and the valve F thus cuts off steam earlier, as required to reduce the speed of the engine.

If the slotl were carried to the horizontal line of the axis of the' shaft E, then the pin f, in occupying this position, would transmit no motion to the rod F and the cut-od valve. If, thevalve F then has the length required to cover both openings, in the valve B, steam may be cut off entirely. y

'Ihe governor G is operated in any manner deemed advisable. In order that it may readily act to move the pin f, as above required, and the valve FI have arranged to partially balance said valve, by cutting the valve-seat A shorter than the valve B, thus admitting steam under the ends, at a', to the openings b, and relieving the pressure against the cut-olf valve for the area of said openings.

Similarly, in the upper surface of the valve'B, I arrange the passage b', to enter the steam under the valve F, and thus afford a second reduction of pressure.

In case the governor" is not used, a hand-lever may be employed to move the pin f and rod F, and thus the cut-off movement of the valve F is'regulated in saw-mill and similar engines.

Having thus fully described my invention,

What I claim, isglp The cam-plate L, pivotcd at E, and vibrated by rthe connecting-rod M and an eccentric from the shaft.

2. The cut-ofi' valve F, operated through the eam- A, the latter having the curtailed ends a', substantially plate L, by the eceentrleon the shaft 0, with the main as set forth. valve- B, operated through the lever d, pivoted at the same shaft E, with the cam-plate L, all arranged and constructed substantially as set forth.

3. The valve B, construetedwith the passage b and v openings b, and arranged with the valve F and the seat' my hand, iu t-he presence of- Witnesses: GEO. MILBANK.

GEORGE P. HERTHEL, Jr., WILLIAM W. HERTHEL.

In witness of said invention, I have hereunto set 

